The operating principle of MEMS components is as follows.
By means of a drive electrode, an electrostatic force is exerted on a mechanical object of very small dimensions disposed in the vicinity of a radiofrequency transmission line. The displacement or the deformation of the object subjected to this force causes an electronic parameter, which is usually a resistance or a capacitance, to vary. This variation interrupts or restores the transmission of the radiofrequencies in the transmission line. An embodiment of this type of switch is disclosed in FR2930370.
To produce a breaker of capacitive type, suspended-membrane or “bridge” devices are preferentially used.
The operating principle of this type of device is described in the simplest case of the use in micro-breaker, and, is illustrated in FIGS. 1a and 1b which represent respectively a so-called “high” state in which the signal passes and a so-called “low” state in which the signal is short-circuited.
More precisely, a membrane or a metallic beam 1 of small thickness, of the order of 1 μm, is held suspended by pillars 2a, 2b above a radiofrequency transmission line 3 which is produced on the surface of a substrate 4 and in which a signal Sig is propagated.
A dielectric layer 5 is deposited on the surface of the transmission line 3. Conducting lines 6a, 6b, also called ground planes 6a; 6b, are connected to the transmission line 3 and are linked to ground M, not visible in FIGS. 1a and 1b. 
The membrane 1 can be subjected to an electrical voltage by means of a drive electrode.
In the absence of applied voltage, the membrane 1 is suspended above the transmission line 3 at a first height or at a first “gap” that may be likened to a first capacitance, typically the first height is greater than 1 micron.
When a sufficiently high electrical voltage is applied to the drive electrode, the membrane 1 is subjected to an electrostatic force which deforms it. The membrane 1 is then separated from the transmission line 3 by a dielectric layer 5 forming a second capacitance which is much greater than the first capacitance formed by the first air gap. Consequently, the radiofrequencies are short-circuited to ground M.
According to the electronic setup, the variation of this capacitance can be used to produce a micro-breaker.
Several studies have demonstrated that when the membrane of an RF MEMS is in the low state, or, in other words, when the RF signal is short-circuited to ground M, relatively sizable electric currents flow in the membrane 1.
FIG. 2 is a graphical representation of a simulation of the densities of current generated in the membrane 1 as a function of the region of the membrane 1 considered when the latter is in the low state, or, in other words, when the signal Sig is shunted or diverted to ground M.
The membrane 1 is defined according to two axes: a first axis Ox has a direction parallel to the direction of propagation of the signal Sig in the transmission line 3, and, a second axis Oy has a direction perpendicular to the direction of propagation of the signal Sig in the transmission line 3.
According to the direction of the axis Ox, three successive zones can be defined:
a first zone Z1 exhibiting a high current of the order of 800 mA
a second zone Z2 exhibiting a lower current than that observed on the first zone Z1, the measured currents being of the order of 400 mA
a third zone Z3 exhibiting almost zero currents.
FIG. 3 is a schematic representation of a membrane 1 in which a signal Sig flows when the membrane 1 is in the low state.
The passage of the signal Sig generates a potential difference between the parts of the membrane 1 opposite the RF transmission line 3 and the parts of the membrane 1 opposite the ground planes 6a; 6b. 
A current density generating a localized temperature increase is then created in the parts of the membrane 1 which link the transmission line 3 to the ground planes 6a; 6b. It is thus possible to define four zones Z1a, Z1b, Z3a and Z3b corresponding to the boundaries of the parts of the membrane 1 which link the transmission line 3 to the ground planes 6a; 6b when the membrane 1 is in the low state.
The current densities generated are dependent on the applied frequency. For frequencies of the order of about ten gigahertz, the currents are estimated at between 0.5 to 1 A.
Similarly, these zones of larger current density are observable when the membrane is in the high state, or, in other words, when the signal passes. However, the differences in current densities between the zones of large and of small current densities are less sizable.
Generally, RF-MEMS components are subjected to a voltage of the order of 10V to allow switching. Under these conditions of use, there is no risk of the membrane 1 being damaged through the temperature rises due to the flow of the current in the membrane 1.
On the other hand, when the power of the signal Sig or the electrical voltage of the order of 30 to 50 V or the frequency of the signal Sig is increased, the flow of the current in the membrane 1, when the latter is in the low state, in particular, causes a sizable increase in the temperature of the membrane 1, and, especially in the zones Z1a, Z1b, Z3a and Z3b in which large current densities are observed, typically the membrane 1 boundaries situated on either side of the transmission line 3, or in other words, opposite the part of the substrate 4 in direct contact with the air of the air gap or on the parts of the membrane which link the transmission line 3 to the ground planes 6a; 6b. 
The application of a high power, typically greater than or equal to 15 W, to RF-MEMS risks causing the membrane 1 to burn and leads to immediate failure of the capacitive RF-MEMS.